1jz hilux getting hot!!!

[jakwoo39]

i have a hilux that ive put a 1jzgte into as in the picture it has single turbo and currently tuned on a low 6psi still making 300bhp but my problem is cooling the thing.
the problem is i mounted the motor back as far as possible then mounted radiator right on motor then fan on rad and intercooler pretty much touching fan

the radiator is a brand new alloy hilux one (old one in pic) and it still isnt cooling enough.

tomorrow i will be lifting the back of the bonnet to let hot air out but id be supprised if this is enough so any suggestions on how i can cool the thing down, the only other idea i had was to run quad radiator off heater hoses to aid the situation

[Crash bandicoot]

you need to increase the volume of coolant.

either a larger core or mulitiple cored radiator or the orignal rad out of the car or a header tank that is within the coolants pressure circut around the system. You can guarantee with such a tight space no amount of big arsed fans will keep the temp down.

Had the same issue with a RB30dett in a LN56. Solved it by using a cut down mack truck intercooler, the new radiator held about 15 litres itself over the orignal 12 litres in the block and radiator etc.

[jakwoo39]

there is simply no room for a bigger radiator can go wider because of piping cant go up or down because of bonnet and cross member and cant go thicker because of the motor. what exactly do you mean by header tank? wont this just take longer but still eventually heat up???

[Petemcc]

I take it it's not running too lean?

[shortylux]

Well you are going to have to compromise on something.

Looks like there is a bit of space such that you could remake your piping and fit a wider rad.

Chop the cross member out and remake something such that you can sit the rad lower and fit a taller rad in. (I did this in my Lux, even had half the rad cap sticking out through a small hole in the bonnet. Looked a bit dumb but did not over heat)

Do a body lift so you can fit a taller rad.

Rear mount the rad so you can fit what ever the hell you like (in theory).

Ditch the intercooler so that you can fit a wider rad.

Does the rad fan have a proper shroud? Or is the fan hard up against the rad so nothing to shroud. Is it just a pancake fan?

Move the motor back so you can fit a mechanical or proper elec fan. (I know you said the motor is back as far as poss, but that is a relative statement. With enough reason/need/desire I'm sure you could move it back another 100mm)

[BlakeNZ]

Does your unwrapped exhaust run real close to that steel water pipe at the back of the JZ motors?

[cornflake]

what is between the radiator and the inter cooler

[ToyRover]

are you using a 3 core radiator?

[slidenyo]

davies craig ewp,
3 core surf radiator ensure its set up with passes in the tanks so the coolant does some laps in there.
get rid of the front mount or paint it black at least (imo).
hpc the dump pipe .

[bang-thud-thump]

Let it suck cold air too.

[Trundle]

Having owned a 3 litre petrol turbo surf and i have customers with 1jz surfs with no issues do the following ,

1, Your radiator looks older than the arc , Get a new 3 core one , or at a minimum get the top tank removed and flushed ,

2, Fit a genuine toyota thermostat as they are bypass style and its important that you do as the dimentions are shit on the aftermarket ones ,

3, make a shroud for you electic fan so it actually pulls air acros the whole radiator no just where its mounted to ,

4, make sure the radiator cap is sealing correctly ,

5, pressure test the cooling system for leaks ,

6, ensure the fan is pulling the right direction and that it has a solid 12v at least supply with decent cables ,

If that doesnt fix the problem , Do a cylinder leakdown test or it could be a simular issue , Keep in mind that copper raidators dissapate heat over 20 percent bettter than alloy ones ,
My race cars run electric water pumps but they are not suitible for your application ,
I can not forsee it overheating if you fix all those issues ,
If it does and the tune and motor condition is in check , Go to a wreckers and get a commodore or other factory fan that has an epically big motor and shroud on it ,

[Trundle]

Having owned a 3 litre petrol turbo surf and i have customers with 1jz surfs with no issues do the following ,

1, Your radiator looks older than the arc , Get a new 3 core one , or at a minimum get the top tank removed and flushed ,

2, Fit a genuine toyota thermostat as they are bypass style and its important that you do as the dimentions are shit on the aftermarket ones ,

3, make a shroud for you electic fan so it actually pulls air acros the whole radiator no just where its mounted to ,

4, make sure the radiator cap is sealing correctly ,

5, pressure test the cooling system for leaks ,

6, ensure the fan is pulling the right direction and that it has a solid 12v at least supply with decent cables ,

If that doesnt fix the problem , Do a cylinder leakdown test or it could be a simular issue , Keep in mind that copper raidators dissapate heat over 20 percent bettter than alloy ones ,
My race cars run electric water pumps but they are not suitible for your application ,
I can not forsee it overheating if you fix all those issues ,
If it does and the tune and motor condition is in check , Go to a wreckers and get a commodore or other factory fan that has an epically big motor and shroud on it ,

[jakwoo39]

Sorry guys went on holiday and forgot about this

And I need to clear a few things up I have a brand new 2 core radiator in it there is no room to go thicker as the rad sits 5mm off motor fan sits on rad and intercooler sits just off fan
Can't go wider as the piping will hit headlights (surf front) and rad support panel only has certain sized hole for rad anyway
And can't go up and down as 2wd hiluxs have suspension bracing

I have brand new
Radiator
Water pump
Genuine thermostat
Rad hoses
Rad cap

And the motor has been leak down tested and compression all good

So my thoughts were that the intercooler restricts flow too much or the radiator simply isn't big enough

I don't want to remove the intercooler as high inlet temps can bring on detonation.

So with that in mind what do people think about either a water to air intercooler so I can remove the air to air and have a bigger radiator

Or run dual radiators (second in the valance) the only road block with this is I can't find a long thin radiator only intercoolers but I don't think they cool we'll enough

[Trundle]

Get a decent quality fan that pumps some air and fabricate a shroud to cover the whole radiator , Also what size turbo is on it and how much boost are you running , ? If the exhaust housing is to restrictive you may be getting exessive heat from there , Ct26 cause heating issues much over 14psi on 1jz

[jakwoo39]

Will get onto shroud next week unsure of brand on fan but does take up the whole height of the radiator
The turbo is a t3t4
Stainless manifold
38mm external gate
The turbo now has turbo beanie and fully heat wrapped

And is only running 6psi

[meatc]

If I am reading this right your fan is in between the intercooler and radiator. A shroud will not help here.

First thing is just check the fan is designed to run as a push fan and is running in the right direction.

Second can you take the fan out move the radiator forward enough to fit a decent engine driven fan? The push fan is not going to be as efficient as a well shrouded pull fan particularly when it is trying to pull through the cooler and then push through the rad.

[Trundle]

If the fan is not directly on the radiator , i.e its attatched to the intercooler that then forces air through the radiator that is your problem !

[jakwoo39]

Sorry the fan is on the front of the radiator ie pushing air through

So it goes
Grille
Intercooler
Fan
Radiator
Engine

Fan is attached to radiator and has straight blades so should do both directions

If I am reading this right your fan is in between the intercooler and radiator. A shroud will not help here.

First thing is just check the fan is designed to run as a push fan and is running in the right direction.

Second can you take the fan out move the radiator forward enough to fit a decent engine driven fan? The push fan is not going to be as efficient as a well shrouded pull fan particularly when it is trying to pull through the cooler and then push through the rad.

Hadn't considered that is an engine fan a lot better than electric???

[BlakeNZ]

yes a 1jz clutch fan (with shroud) is much better than most electrics. A twin fan set up(with shroud)pulling air through (like found in falcon XR8s) may be its equal.
However... you (currently)have no room for a factory 1jz fan:(
You need to answer my question regarding the down pipe heat shielding and location.

[jakwoo39]

Sorry the pipe that runs around the motor is only used for the heater so only has water flowing when heater is on.
Exhaust is now wrapped anyway

[jakwoo39]

Ok problem solved now i have a secondary radiator under the ute tray. coolant comes out of motor into front radiator then to the back radiator (flows through both) and now the highest temp iv had is 90 degrees when i took it for a good thrash and left it to idle for 30 mins.

my only thought now is weather to over drive the water pump pulley just to help things along as the pump has to move water a very long distance. it wont cost me any to make 1 but will be alot of time to do the multi rib

[shortylux]

Cool solution. Any pics?

I have no info for you re over driving other than I have made mine about 13% smaller. My truck won't be running for a year though so no idea if it works. Don't go to fast as you dont want to cause any cavitation.

[Big]

Ok problem solved now i have a secondary radiator under the ute tray. coolant comes out of motor into front radiator then to the back radiator (flows through both) and now the highest temp iv had is 90 degrees when i took it for a good thrash and left it to idle for 30 mins.

my only thought now is weather to over drive the water pump pulley just to help things along as the pump has to move water a very long distance. it wont cost me any to make 1 but will be alot of time to do the multi rib

You have givin me an idea.. But I don't think over driving the pump will help any as.. it still pushing the right amount of water be it from a small source or bigger source.. makes no difference water in water out and the same speed regardless of length and it'll be an advantage longer as more reserve of cooler water and more time cooling in the radiators. my 2cents

[Mattman]

You will be increasing the back pressure in the system by increasing the volume of water but as the pump is engine driven it shouldn't matter at all.

I wouldn't bother modding the pump unless you still have issues.

Matt.

[jonossiksilvia]

+1 for pictures of setup now

[Crash bandicoot]

As for over driving the pump i wouldn't bother. It's a catch 22.
Make it flow faster less time to cool down
Flow slower more time to cool down.

And don't be to concerned about the extra volume having an effect on the pumps ability to do it's job as you have to remember the physics of it...It's in a push pull situation, A closed loop means what ever volume the pump has to push it is also going to suck in from the bottom radiator hose.